Metal sawing machine



' Aug. 24,1943.

METAL SAWI'NG MACHINE Filed July 25, 12541 '7 Sheets-Sheet 1 ow/AAMKMMQ M] v lN\-'ENTOR. JOHAN GUSTAF MOOHL ATTORNEYS Aug. 24, 1943. J. G. MOOHL METAL SAWING MACHINE 7 Shets-Sheet 2 Filed July 25, 1941 JHIHHHHH INVENTOR. JOHAN GUSTAFMOOHL 05-01142, W "a ATTORJJE Y5 1943- .)..G; MOOHL 2,327,920

METAL SAWING MACHINE Filed July 25, 1941 7 Sheets-Sheet 3 4 2 INVENTOR. II-E JOHAN GUSTAFMOOHL ATTORNEYS Aug. 24, 1943. J. G. MOOHL 2,

- METAL SAWING mcnmn" 7 Filed July 25, 1941 '7 Sheets-Sheet. 4

FIE--4 INVENTOR. JQHAN GUSTAF MOOHL ATTORNEYS OW, s 190w Aug. 24, 1943.

J. G. MOO HL METAL SAWING MACHINE Filed July 25. 1941 7 Sheets-Sheet 5 INVENTOR.

JOHAN GUSTAFMOOHL BY I m, a ATTORNEYS Aug. 24, 1943. J, G, MQ HL 2,321,920

METAL SAWING MACHINE INVENTOR. JOHAN GUSTAF MOOHL ATTORNEYS Aug'. 24, 1943. J. G. MOOHL METAL SAWING MAC HINE Filed July 25, 1941 7 Sheets-Sheet 7 INVENTOR.

JOHAN GUSTAF MOOHL ATTORNE Patented Aug. '24, 1943 2,327,920 METAL SAWING MACHINE Johan Gustaf Moohl, Cleveland Heights, Ohio,

assignor to The Motoh 8a Merryweather Machinery Company, Cleveland, Ohio, a corporation of Ohio Application July 25, 1941, Serial No. 404,020 8 Claims. (Cl. 29-439) The present invention relates to a, machine for cutting off or sawing metal wherein a circular disc saw, mounted upon a movable carriage, is traversed through the work-piece or metal to be out, which, in turn, is held stationary in a workholding clamp or vise. The general object and nature of my invention is to provide such machine having improved operating efliciency, increased productive capacity and greater workhandling facility.

A further objective of my invention is to incorporate certain safety features in the machine for the purpose of substantially reducing the likelihood of injury or accident to the machine operator.

The foregoing, as well as additional objectives and advantages of my invention, shall be described in detail as the following description proceeds.

To the accomplishment of the foregoing and related ends said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. l is a front end elevational view of a metal sawing machine embodying the improvement of my present invention; Fig. 2 is a side elevational view of the machine shown in Fig. 1; Fig. 3 is a detailed sectional view of the work-holding vise and associated operating mechanism; Fig. 4 is a detailed View, partially in section, of the mechanism for supporting the work as it is conveyed to the work-holding vise; Fig. 5 is a sectional view taken along the line 55 of Fig. 4; Fig. 6 is a detailed elevational View of the vise hand-adjusting wheel; Fig; '7 is a detailed, sectional view of the hand control lever and of the machine-actuated mechanism for controlling the saw carriage feed; Fig. 8 is a detailed, sectional view taken substantially along the line 8-8 of Fig. '7; Fig. 9 is a detailed, sectional View taken substantially along line 9-9 of Fig. 7; Fig. 10 is a vertical, sectional view taken along line Ill-40' of Figs. 7 and 11; Fig. 11 is a sectional view taken upon a plane normal to that of Fig. 10 and substantially along line II-l l thereof; Fig. 12 is a lay-out of the hydraulic pressure system control mechanism of the machine; and Fig. 13 is a diagram illustrating the principle of operation of. the hydraulic control and operating system.

Now referring more particularly to Figs. 1 and 2 of the drawings, the machine therein comprises a base frame I upon which the metal saw 2 is carried by means of the movable saw carriage 3. Driving power is transmitted from the electric drive motor 4 to the saw 2 by means of driving connections and a gear train which need not here be further described in detail. The workholding clamp or vise comprises the lower, vertically fixed jaw 5 and the upper, vertically movable jaw 6. The housing 1 supports the screw shaft 8 carrying the movable jaw 6. A hand wheel 9 is provided for adjustably regulating the vertical position of the shaft 8 and jaw 6. A vertically movable housing I0 is mounted on the side of the frame I and carries a roller II for supporting-and conveying the work-piece W as the latter is moved into position between the vise jaws 5 and 6.

A stock limit stop gauge or bar 12 is adjustably clamped in the end of the arm B which is'keyed to the upper rock shaft l4.- A lever arm 15 connects the shaft M to the connecting rod l6, leading to the bottom rock shaft ll,

which, in turn, is oscillated by means of the foot treadle i8.

As the work-piece W is moved between the jaws 5 and 6, the limit stop gauge i2 is in position as shown in Fig. 2, where it abuts against the end of the work-piece, thus determining the length of stock to be severed. After the workpiece is clamped between the jaws 5 and 6, and the piece of stock cut off by the saw 2, the foot treadle l8 is depressed, thus rocking the stock gauge I2 in a clockwise direction (with respect to Fig. 2), thus clearing the way for the removal of the severed stock from the lefthand side of the machine. When the foot treadle I8 is again released, the stock gauge [2 moves back into its original position to measure and to determine the length for the next piece to be cut.

Work-holding vise The construction of the work-holding clamp or vise and its associated operating mechanism is best illustrated in Fig. 3. The vertical standard or supporting housing 1 rests upon the machine frame i. A vertical tie bar 20 extends from the top of the housing 1 to the frame I and acts as a tension member adapted to receive the full thrust of the vise jaws 5 and 6 when the latter are in closed or work-holding position, thus relieving the major tension stresses which might clutch connection shown at 24. Rotation of the hand wheel 9, in turn, rotates the quill 2| and thus determines the vertical position of the vise jaw 6 with respect to the vertically movable sleeve 22. In normal operation, this adjustment will be made so that the jaw 6 clears the work-piece W by an inch or so when the sleeve 22 is in its uppermost position, substantially as shown in Fig. 3.

A rocker arm 25 mounted upon the fixed shaft 26 has a toothlike projection 21 which engages in a complementary recess in the sleeve 22. The other end of the rocker arm 25 is engaged in an annular receiving groove in the cylindrical block carried on the upper end of the piston rod 29. The piston rod 29 is carried by the piston 30 which is adapted to reciprocate in the fiuid pressure cylinder 3|. Pressure supply lines or conduits 32 and 33 are connected to each end of the cylinder 3|. A pressure exhaust or relief line 34 is also connected to either end of the cylinder 3|. The relief passage 35 is adapted to be connected with the upper end of the cylinder 3| by means of the by-pass ports 36 in the piston rod 29. The line 3! connects the relief passage 35 to the relief line 34. The relief line 34 is connected to the port 38 in the bottom end of the cylinder 3|. A projecting rod or plunger 39 is carried on the bottom side of the piston 30 and is adapted to fit within the port 38. Small by-pass ports 40 are provided in the end of the plunger 39 whereby the port 38 is placed in communication with the interior of the cylinder 3| when the piston approaches its uppermost position. The operation of the workholding vise as just described, is as follows:

The parts are initially in the position as shown in Fig. 3, with the work-piece resting on the lower, fixed jaw 5., Fluid under pressure, which may be either pneumatic or hydraulic, is introduced through the pressure supply line 32 to the lower end of the cylinder 3|. The piston 30 is thereby forced in an upward direction, rocking the rocker arm 25 in a clockwise direction and moving the sleeve 22, the screw shaft 8 and the movable jaw 6 in a downward direction until it firmly engages and clamps the work-piece W in the vise. At the same time, fluid in the upper end of the cylinder 3| is evacuated out through the line 33. In the event that the vertical position of the movable jaw 6 is not first properly adjusted in order to secure a firm and positive clamping of the work-piece W, fluid pressure is exhaustedthrough the ports 40 and 38 to the line 34 so that it will be impossible to build up a back pressure in the line 32, and thus, to prevent traverse or feeding operation of the saw carriage, as will -be subsequently described. In this manner, any

possibility of light or insecure clamping of the work-piece whereby the latter might be forced or displaced from the work-holding vise to the injury of the machine or the operator, is positively guarded against.

After the work-piece has been cut off by operation of the saw 2, fluid pressure is introduced through the line 33, to the upper end of the cylinder 3|, moving the piston 30 in a downward direction and the movable vise 6 correspondingly in an upward direction. As the piston 3!] approaches the end of its downward or' return stroke, the ports 36 place the relief passage .35 in communication with the upper end of the cylinder 3|, thus relieving pressure out through the lines 3! and 34. In this manner, back pressure is not stored up in the line 33, after the necessary work of opening the work-holding vise has been performed. Such relief of back pressure accomplishes the dual function of eliminating waste of excess power applied to the pressure source, such as the hydraulic pump, and also cooperates with the safety control of the operation of the saw carriage 3, as will be further subsequently described. In other words, it is not possible to start thesaw carriage 3 upon its operating feed or traverse as long as the vise jaw 6 is in open or uppermost position. This feature contributes greatly to the safety of the operation of the machine in that it is not possible, inadvertently, to cause movement of the saw carriage while the operator, when the vise is open, might be performing certain preliminary adjustments thereon in the vicinity of the path of travel of the saw.

Work feed and supporting mechanism The above mechanism is best shown in Figs. 4 and 5. A lever 4| has one end engaging the groove in the cylindrical block 28 and its other end pivotally mounted upon the fixed shaft 42. Movement of the lever 4| is connected through the bar 43 to the rocker arm 44 pivotally mounted to the fixed shaft 45. The righthand or outer end of the rocker arm 44 surrounds the threaded connecting rod 46 which is attached at its lower end to the vertically movable housing H). An adjustable thrust collar 41 is mounted on the upper end of the connecting rod 46 and is adapted to be contacted by the rocker arm 44.

The housing I0 is mounted by means of a dovetailed slide-way to the side of the machine frame I. A work-supporting roller projects above the top side of the housing In and is mounted upon the drive shaft 50 journalled therein. The shaft 50 is connected by means of the taper gears 5| through the shaft 52 and the worm and ear set 53 to the electric drive motor 54.

The operation of the last described mechanism is as follows:

As the piston rod 29 and block 28 is moved in a downward direction, raising the movable jaw 6 to release the work-piece W, the lever arm 4| is likewise moved in a downward direction'and its movement is transmitted through the rod 43 and rocker arm 44 to move the housing In and work supporting roller in an upward direction. As the roller II is moved upwardly, it contacts with the underside of the work-piece W, raising the latter out of contact with the fixed vise jaw 5. The drive motor 54 is then actuated, rotating the roller H in a counter-clockwise direction (with respect to Fig. 4), conveying the workpiece W in a lefthand direction until its end contacts with the stock gauge l2, at which point the vise jaw 6 is caused to move downwardly to clamp the work-piece and concurrently moving the roller II and housing ID to its lowered position out of contact with the underside of the workpiece.

' Saw carriage feed mechanism A connecting rod connects the saw carriage 3 to a piston reciprocable in the fluid pressure cylinder BI mounted in the base frame I of the machine. Reciprocation of the rod 60 thusef .fects movement of the carriage 3 towards and away from the work-holding vise. A four-way control valve 62 of the dumb-bell or spool type, as is well-known to those skilled in the art, has its valve stem connected'by rack and gear 63 to the rock shaft 64, which is, in turn, connected through the bevel gear set 65 to the transverse rock shaft 66 leading to-the front end of the machine. A hand lever 61 is mounted on the front end of the shaft 66. Manipulation of the hand lever 61 is thus effective to shift the spool of the valve 62 to introduce fluid pressure alternately to either end of the cylinder BI to cause feed and return movement of thesaw carriage 33.

The outer end of gear housing 60. The gear is keyed to the outer end of the shaft 64 and engages with the rack on the end ofthe connecting rod I I. A cam track 12, also carried by the end of the rod II is engaged by the cam following roller 13 mounted in the lowerend of the plunger I4 which is loaded by the coil compression spring i5. The pressure of the spring 15 is thus transmitted through the plunger-I4 to the roller I3; to the cam track 12, tO-fijdifi the longitudinal movement of the connectirmv rod II. The connecting rod H (see Figrfilxvcarries the adjustable limit stop collars'TB andsH-and the,f xedlimit stop collars 18 and 19,- respectively. ,I'he-righthand end of the rod]! .iis slidably-;supporte d, in a'boss 80 on the side of the machinetframefl. A downwardly depending bracketpBl from the saw"; arria es has 'a U-' haped yoke. 02; fitting over i the rod 1 I and adaptedzto engage with'the li it collars-I6 and TI. The position of the colla'rsflfi' and "IT-on the 'r'odni I- is adjusted by means ofamechanism comprising a hand lever 83 on thethreaded screw'--84;-which bears against a contact shoe 85. engaging with a flat on the side ofthe rod II.

The operation of the last-described mechanism is as follows:

The limit stop' collars IB'and 11 are preliminai-ily set at positions corresponding to the desired length of travel of the saw carriage 3. The fixed limit stops 18 and '1 9, of course, determine the maximum'range of this adjustment setting. Thelever I51 is then manipulatedto introduce pressure to the head end of the cylinder 6| causing. thesaw carriage to move in a' righthand direction with respect to-Fig. 2 or towards the work-piece. When the saw carriage 3 approaches the end of its working stroke, the yoke 82 contacts with the limit stop collar 11, moving the rod II in a righthand direction. This: causes the roller I3 to move or ride up upon the rise in the cam track 12, compressing the spring 15. As soon as the roller Breaches the top of this rise in the cam track I2, it will, of course, tend to ride down upon the other side of it, urgingt e. rod II in arighthand direction -with'a very rapid movement or.fsnap action, thus rotating; the gear 69 and ,the rock the rock shaft 04 enters the Control system As it should now bequ'ite apparent, the opera tion of those component parts of the machine ,comprising the work-holding vise, the saw carriage and the work-supporting and conveying roller, are interdependent and made to function, one with respect to the other. This is accomplished by means of a control system which is particularly illustrated in Figs. 12 and 13.

Within the base frame I of the machine there are located an electric drive motor, a pressure pump and an oil supply reservoir which, in effect, comprise the source of the fluid or hydraulic pressure for the system. Thus, the drive-motor 00 is connected to the hydraulic pump 9|. The coolant supply pump 92 is also coupled to the motor drive and adapted to deliver the usual coolant medium from the intake line 93 to'the outlet line 94, to the delivery branches 95 and 96, suitably positioned on either side of the circular saw 2. 1

An intake line- 91 leads from the oil supply reservoir 98 to the pump 0 I. The outlet, or pressure delivery side of the pump 9| is connected by the line 99 to the pressure regulating valve I00.

.. A pressure gauge I00 is connected to the regulatingvalve I00 and mounted on the front panel on machine frame I. A return line IOI leads from the regulating valve I00 to the reservoir 98.

,valve I00 (i. e., a pressure. control valve adapted .The line I02leads from. the pressure regulating ;to regulate the amount of pressure delivered from pressure-actuated valve I03.

the pump to the line I02) to the differential The valve I03 is of standard construction and adapted to deliver .fluid to its outlet lines I04 and H0 at. different.

predetermined pressures. predetermined. pressure at set, the line.*;I 02 is Thus, at 'the. lower, which the valve 103 is placed in communication with .the deliverydine I04 leading to the, distributing valvenl05 which, is also of-the standard dumbbell-or ;fspool- --type and whose shiftable spool is actuated by means of a rack and gearconnec- 'tion I00 to the rock shaftID'I leading to the front 'endof the machine where the hand lever I08 is connected-to it; The-pressure delivery lines 32 and-'33 lead-from the distributing valve I05 to the The pressure, relief or return line 34 leads'from the cylinder 3| back to the valve I05. A return line I09 leads from the valve I05 to the reservoir 98.

I At-the highenpredetermined pressure of ithe differential valve-I03, the pressure delivery, line valve 62.,

from the valve carriagefeed cylinder 6I.

' shaft 64 to shiftzthe spoolof the control valve 62 I02-is placed in communication with the delivery linen-H0 leading to the distributing or control Theipressure deliveryline III leads 62 to the head end of the saw The pressure delivery line II2 leads from the valve 52 to the check. valve-I I3 and; thence, through the line I I4 to the rod end of the cylinder BI. The check valve I I3 is 'adaptedto permit flow only in a direction from the line II2 to the line H4, and not in a reverse direc'tion.

The line II5 connects the lin II4 to the flow control Valve I I6, which, in turn, is connected by the line M1 to thedeliv'ery line I I2.

Thus, as pressure is i troduced from the' control valves 62, through the delivery line III to the head end of the cylinder 6|, the speed or rate of movement of the piston and piston rod 60 in a direction corresponding to the saw carriage feed, is controlled by the action of the flow control valve II 6 which determines the rate at which the fluid is evacuated from the rod end of the cylinder 6|. If the flow control valve H6 is set at a relatively high rate, the rate of traverse of the saw feed carriage 3 will be correspondingly greater. Conversely, a relatively lower flow rate setting of the flow control valve I I6 will function to decrease the speed of the saw carriage feed.

This last described feed rate control particularly contributes to the safety and efliciency of operation of the machine in that it permits the proper regulation of the rate of saw feed for metals of varying hardness and cross-sectional size.

An exhaust line I I 8 from the flow control valve H6 connects to the exhaust line H9 from the valve 62, leading to the supply reservoir 98. A cam I20 is mounted upon the rock shaft I01 and is adapted to actuate the push rod I 2| of the electric switch I22 connected in the electric circuit comprising the supply lines I23 and I 24 leading to the drive motor In for the work-supporting roller II. Thus, as the hand lever I08 is manipulated to open the movable jaw 6 of the workholding vise, the motor I is correspondingly actuated to rotate the roller I I, and as the jaw 8 is closed, the motor III and the roller II are correspondingly stopped.

Directing attention particularly to Fig. 13, it will be seen that pressure cannot be delivered to the delivery line IIll leading to the saw carriage feed control valve 62 unless and until sufiicient pressure is developed in the diiferential control valve I03. Such pressure is developedonly if the piston 30 is at rest in a position short of the end of its upward or working stroke, where the vise jaw 6 is firmly and positively clamped against the work; otherwise pressure is relieved out through the by-pass port 38 to the relief line 34. On the other hand, sufiicient back pressure cannot be developed in the line. I04 to actuate the valve I 03 to connect the line I II) for operation of the saw feed carriage when the piston 30 is, at any point, on

source, valve means for introducing fluid under pressure alternately to each end of said cylinder, at by-pass port in one end of said cylinder leading therefrom to pressure discharge, and means carried by said piston for opening said port at a point adjacent the end of its stroke in a direction away from said one end of said cylinder.

3. In a metal sawing machine, a work-holding vise comprising a fixed jaw and a movable law, a fluid pressure cylinder having a piston connected to said movable jaw, a pressure supply source, valve means for introducing fluid under pressure alternately to each end of said cylinder, a by-pass port in one end of said cylinders leading therefrom to pressure discharge, and a projecting plunger on the end of said piston adapted to enter into and to close said port during the majority of the working stroke of said piston and to open said port at a point adjacent the end of such working stroke.

4. In a metal sawing machine, a work-holding vise comprising a fixed jaw and a movable jaw, a fluid pressure cylinder, a piston reciprocable in said cylinder, a piston rod connecting said piston its downward or return stroke, which is effected by introduction of pressure through the delivery line 33. Thus, as the piston 30 reaches the end of its downward stroke, pressure is relieved through the by-pass ports 36 to the return lines 3'! and 34.

Other modes ofapplying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. In a metal sawing machine, a work-holding vise comprising a fixed jaw and a. movable jaw,

a fluid pressure cylinder having a piston connected to said movable jaw, a pressure supply source, valve means for introducing fluid under pressure alternately to each end of said cylinder,

and means carried by and movable with said piston for relieving fluid pressure in each end of said cylinder when said piston reaches a predetermined point in its travel adjacent the opposite end of said cylinder.

2. In a metal sawing machine, a work-holding vise comprising a fixed jaw and amovable jaw, a fluid pressure cylinder having a piston connected to said movable jaw, a pressure supply second pressure-actuated means to said movable jaw, a pressure supply source, valve means for introducing fluid under pressure alternately to each end of said cylinder, by-pass' ports in each end of said cylinder, one of said ports being adapted to be opened and closed by registering ports in said piston rod, and a projecting plunger on the head end of said piston adapted to enter into and to open and close the other of said ports.

5. A metal sawing machine comprising a workholding vise, a saw carriage movable with respect to said vise, a fluid pressure-actuated means for operating said vise and a second fluid pressure-actuated means for moving said carriage, a single pressure supply source, pressure control means for introducing fluid under pressure from said source to said first-named pres-- sure-actuated means prior to introduction to said and valve means mechanically connected to and actuated by movement of said first named pressure-actuated means for relieving presure therein, when said vise is in fully opened position.

6. A metal sawing machine comprising a, workholding vise, a saw carriage movable with respect to said vise, a pressure cylinder and piston therein connected to said vise for opening and closing the latter, a second cylinder and piston therein connected to said carriage for moving the latter, a pressure supply source, control valves connected to each of said cylinders, a valve actuated by a pressure diflerentlal connecting said pressure supply source to both of said control valves whereby pressure is introduced to one of said control valves prior to introduction to the other and a pressure relief valve formed by ports in said first-named piston and adapted to be opened automatically by movement of said piston in said first named cylinder to a position corresponding to fully opened position of said vise.

7. A metal sawing machine comprising a workholding vise, a saw carriage movable with respect to said vise, a presure cylinder and piston therein connected to said vise for opening and closing the latter, a second cylinder and piston therein connected to said carriage for moving the latter, a pressure supply source, control valves connected to each of said cylinders, a valve actuated by a pressure differential connecting said pressure supply source to both of said control valves whereby pressure is introduced to one of said control valves prior to introduction to the other, manually actuated means for operating each of said control valves, a work supporting roller mounted adjacent said vise, an electric motor for rotatably driving said roller, an electric control switch for actuating said motor, and

means connecting said switch to that one of said manually actuated means which operates said control valve for said first-named cylinder,

8. In a metal sawing machine, a work-holding vise comprising a fixed jaw and a movable jaw, a vertically movable work support mounted adjacent said fixed jaw, a work-contacting roller carried by said work support, an electric motor for rotatably driving said roller, an electric control 

